Study of ethosuximide detection using a novel molecularly imprinted electrochemiluminescence sensor based on tris(2,2′-bipyridyl) ruthenium (II)@nitrogen doped graphene quantum dots

A novel molecularly imprinted electrochemiluminescene (ECL) sensor was fabricated for the detection of ethostucimide. The new Ru(pby)(3)(2+)@N-GQDs (tris(2,2'-bipyridyl) ruthenium(10@nitrogen doped graphene quantum dots) nanocomposite was synthesized by electrostatic interaction between Ru(pby)(3)(2+) and N-GQDs, which showed excellent and stable ECI, properties. And then dopamine as functional monomer and ethosuximide as template molecule were co-polymerized by hydrogen bonding on the surface of Ru(pby)(3)(2+)@N-GQDs/Nafion. After ethosuximide was extracted with H2SO4, the molecularly imprinted cavities in film were formed. When ethosuximide rebound onto imprinted cavities again, the ECL intensity of Ru(pby)(3)(2+)@N-GQDs decreased. Based on this principle, the quantitative relationship between the concentration of ethosuximide (c) and the variation of ECL intensity (Delta I-ECL) was established. Namely the Delta I-ECL depended linearly on the log c in the range from 5.00 x 10(-7) to 1.00 x 10(-4) mol/L with a detection limit of 3.00 x 10(-7) mol/L (S/N = 3), and the correlation coefficient was 0.9984. The proposed sensor was also applied in plasma and urine samples with recovery in range from 97.80% to 106.2% (RSD < 6.3%).